Faecalibacterium prausnitzii

Transcription

1 Faecalibacterium prausnitzii is an anti-inflammatory commensal bacterium identified by gut microbiota analysis of Crohn disease patients PNAS 105(43): , Speaker: Ming-Cheng Chen Advisor: Chii-Shen Yang, Ph.D. Date: 05/26/2009

2 1 Introduction of the Crohn disease inflammatory bowel disease (IBD) autoimmune disease affect any part of the gastrointestinal tract in westen country, 1/1000 population get the disease The exact cause of Crohn disease is still unknown!

3 2 The common sites involved in Crohn disease Ileal Ileocolic Colonic

4 3 Symptoms Diarrhea Blood in your stool Ulcer At risk of malnutrition Reduced appetite and loss weight Also increases the risk of cancer in the area of inflammation

5 4 Treatments and drugs Actually,there is no cure for Crohn disease. Anti-inflammatory drugs Immune system suppressor Antibiotics Others : anti-diarrheals pain relievers Surgery

6 5 Some possible theories for the disease The exact cause of Crohn disease is still unknown! 1) Persistent pathogenic infection 2) Dysbiosis 3) Defective mucosal barrier function 4) Defective microbial clearance 5) Aberrant immunoregulation

7 6 Some important factors of the disease Genes : CARD15 Environment: smoking Immune system Microbes imbalance

8 7 The possible pathways for patients to get the Crohn disease Crohn disease

9 8 Gut flora in human body normally live in the digestive tract of animals has about ten times number of microorganism than human cell in the intestines some bacterium are thought to be capable of causing disease by causing infection or increasing cancer risk for the host

10 The functions of gut flora 9

11 10 In the previous study 16S rrna microarray compare the differences between normal people and patients microbial distribution in faecal

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13 12 Framework Is the disease related to specific bacteria? What is the role of the bacteria in inflammatory response? Which portion of the bacteria is functional? Can the specific molecule counterbalance the dysbiosis in colitis mice? Is it possible to use the bacteria to reduce the mortality of colitis mice?

14 Is the disease related to specific bacteria? 13 Compare the F. prausnitzii distribution of recurrence and non-recurrence patients A lower proportion of F. prausnitzii on resected ileal Crohn mucosa is associated with endoscopic recurrence.

15 14 peripheral blood mononuclear cell (PBMC) Add different kinds of bacterium T cell B cell IL 6 TNF α IL 12 PBMC culture medium IL 10 Monocyte Cytokine

16 What is the role of the bacteria in inflammatory response? 15 F. prausnitzii shows anti-inflammatory effects on peripheral blood mononuclear cell (PBMC) Proinflammatory cytokines : IL12, IFN γ Anti-inflammatory cytokine : IL10 used to distinguish between strains exhibiting inflammatory regulation property

17 16 Which portion shows anti-inflammatory effect? DNA Cell membrane Cytoplasm Add different portion of bacteria into culture medium Caco-2 reporter cell line Supernatant

18 Which portion of the bacteria is functional? 17 F. prausnitzii supernatant abolishes NF-κB activation in Caco-2 reporter cell line (1)(2) (3) (4) (4) (1) (2) (3) Supernatant of F. prausnitzii, have the antiinflammation property. The influence on NF-κB activation was tested by the SEAP reporter system Secreted Alkaline Phosphatase Assay System ( SEAP )

19 18 Using TNBS-induce mice to mimic the symptom of crohn disease in human Inject TNBS TNBS=2,4,6-trinitrobenzene sulfonic acid Colitis mice

20 19 F. prausnitzii exhibits anti-inflammatory effects on TNBS-induced colitis mice Living F. prausnitzii or its supernatant result in a attenuation of colitis with reduced weight loss. Proinflammatory cytokines : IL12, TNFα Antiflammatory cytokine : IL10

21 Can the specific molecular counterbalance the dysbiosis in colitis mice? 20 F. prausnitzii and its supernatant tend to counterbalance the TNBS-induced dysbiosis in colitic mice Treatment with either F. prausnitzii or its supernatant tended to counterbalance the dysbiosis observed in colitis control mice for bacteria: C. leptum, C. coccoides, Bacteroides, and F. prausnitzii.

22 Is it possible to used the bacteria to reduce the mortality of colitis mice? 21 F. prausnitzii and its supernatant can act by a gut-independent route survival rate of 20 days after colitis induction supernatant 100 % F. parausnitzii dexametasone butyrate colitis control 50 % 10 % i.p.(intraperitoneal) injection In the groups treated with live F. prausnitzii or its supernatant, the mortality rate was dramatically decreased. dexametasone butyrate

23 22 Summary Is the disease related to specific bacteria? What is the role of the bacteria in inflammatory response? Which portion of the bacteria is functional? Can the specific molecular counterbalance the dysbiosis in colitic mice? Use F. prausnitzii as a probiotic to counterbalance dysbiosis is a promising strategy in Crohn disease treatment! 100 % Is it possible to used the bacteria to reduce the mortality of colitic mice?

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